The present disclosure relates generally to fault detection and isolation in complex networked systems and more specifically, to system level fault diagnosis for an air management system of an aircraft.
In general, advancements in sensing and control technologies have facilitated the development of complex networked systems. Complex networked systems consist of multiple sub-systems that in turn consist of components, heterogeneous sensing devices, and feedback controllers interconnected through various electrical, mechanical, hydraulic or pneumatic connections. The complex interconnections and feedback control loops of the complex networked systems make fault detection and isolation a very challenging task.
For example, a complex networked system, such as an air management system of an aircraft, controls and supplies pressurized air to the aircraft and consists of multiple sub-systems. If the complex interconnections and feedback control loops include a faulty component, the faulty component yields off-nominal outputs that are inputs to other coupled components. In turn, the other coupled components that are otherwise healthy produce off-nominal outputs, thus causing unwanted false-alarms. Furthermore, due to off-nominal inputs, the healthy components are driven beyond their normal operating conditions that may lead to cascading failures. Also, the built in controller will use the faulty signals and will mask the faults present in the system for continual operation.